Table 3. Scope of the Diastereoselective Multicomponent Reaction^a–^c.

^aReaction conditions: 1 (0.1 mmol), 2 (0.1 mmol), 3 (0.25 mmol), 4 (0.35 mmol), Sc(OTf)₃ (20 mol %), dry Py as the solvent (2 mL), 70 °C, N₂ atmosphere. The yield refers to isolated products, and dr values were determined by ¹H NMR analysis of the crude reaction mixture.

^bOnly one arbitrary enantiomer of the racemic mixture of the major diastereoisomer is shown.

^cThe relative stereochemistry was determined by NOE-based NMR experiments (see the Supporting Information).